The present invention relates to communication of data. More particularly, the present invention relates to methods and apparatus useful in logic devices for adjusting a message, attachment, or data file size prior to transmitting. In a specific embodiment, the invention provides a unique user interface.
Multimedia messaging systems that can integrate and deliver voice, email, fax, and/or other data are increasingly of interest in environments with installed local area networks (LANs) that have sufficient bandwidth. One such known system is the Xpressions™ unified messaging system, available from Siemens Information and Commnunication Networks, Inc. Common multimedia messaging applications are message delivery software applications that can deliver one or more of a variety of messages, such as voice mail messages, which are generally stored as WAV, RealAudio, or other digitally-encoded audio files. Some multimedia messaging applications can-also deliver other types of digitally encoded files, such as video, still images, facsimiles, or executable files.
Some types of multimedia messages can result in much larger files for transmission than typical text messages. Due to the relatively large amount of digital data generally used to represent voice, for example, a voice mail message of just a minute can result in a large file.
When accessing such a large file for playback over an institutional LAN with substantial available bandwidth, minimal delay is incurred. Typical LANs available today have maximum design bandwidths of 10 Mbps to 100 Mbps, with future designs planned of 1 Gbps. In contrast, remote connection to an institutional server, either from a home or while travelling, is often accomplished over a public telephone network using a modem (sometimes referred to as POTS, for plain old telephone service). A typical fast modem speed or bandwidth is 56 Kbps, substantially slower than the speed or bandwidth of a typical institutional LAN. Other remote connection methods, such as wireless, ISDN, or DSL, also can be substantially slower than LAN speeds. As a result, when a user attempts to access multimedia emails from home or while travelling, a voice mail message of one minute can take several minutes to download. Commonly-owned patent application Ser. No. 09/516,689 entitled Apparatus and Method for Adjustable Data Rate in Multimedia Messaging Systems, filed concurrently herewith, discusses prior art and novel methods for addressing the above problem using a second connection or channel (such as a second phone line or ISDN channel). While a second channel may be available at some locations, such as a home or satellite office, a second channel will often not be available at other locations, such as at a hotel room or an infrequently used home office.
Variable compression techniques are known for some audio and video transmission technologies. These techniques have generally been applied to continuous-stream type of communications, such as a phone call or video transmission. Under these techniques, available channel capacity is detected and compression of video or audio is adjusted to fit available bandwidth. As known in the art, increased compression is generally associated with reduced fidelity in the compressed signal. Such systems are not effective for file systems or multimedia message systems, where different compression amounts and formats may be appropriate or desired for different file formats or file lengths. One example of a variable compression technique for delivering video over a network is discussed in U.S. Pat. No. 6,014,694 issued to Aharoni et al. In conmnon with some other prior art techniques, this method relies on a specific encoding format that can add and drop levels of data based on congestion in the channel. The Aharoni et al. patent also discusses measuring channel bandwidth dynamically during transmission and adjusting transmission until the sending bandwidth is equal to the receiving bandwidth.
What is needed is a method or an apparatus that can provide an acceptable means for accessing large data files, such as multimedia messages or other compressible data, over a reduced bandwidth channel.